<!DOCTYPE html>
<html lang="cn">
<head>
    <meta charset="UTF-8">
    <title>旋转方块</title>
    <style type="text/css">
        .bottom {
            width: 300px;
            height: 300px;
            background-color: black;
            border: 1px white solid;
            position: relative;
        }

        div > div {
            width: 100px;
            height: 100px;
            border: 1px red solid;
            position: absolute;
            left: 100px;
            top: 100px;

            animation-name: square;
            animation-duration: 1s;
            animation-iteration-count: infinite;
            animation-timing-function: ease-in-out;
        }

        @-webkit-keyframes square {
            0% {
            rotate(0 deg);
            }
            100% {
            rotate(360 deg);
            }
        }

        div>div:nth-child(2) {
            animation-delay: 0.1s;
        }

        div>div:nth-child(3) {
            animation-delay: 0.2s;
        }

        div>div:nth-child(4) {
            animation-delay: 0.3s;
        }

        div>div:nth-child(5) {
            animation-delay: 0.4s;
        }

        div>div:nth-child(6) {
            animation-delay: 0.5s;
        }
    </style>
</head>
<body>
<div class="bottom">
    <div></div>
    <div></div>
    <div></div>
    <div></div>
    <div></div>
    <div></div>
</div>
</body>
</html>